Trịnh Cương (chữ Hán: 鄭棡; 9 July 1686 – 20 December 1729) was the lord who ruled Tonkin from 1709 to 1729 (his title as ruler was An Đô Vương).

Like his great-grandfather and predecessor, Trịnh Căn, his reign was mostly devoted to administrative reforms.

Trịnh Cương ruled Việt Nam during a time of external peace but growing internal strife.

This had the effect of increasing the hatred felt by the people towards the Trịnh rulers in Hanoi.

Trịnh Cương passed an edict forbidding people to practice Christianity in 1712.